Tactile feedback is essential for dexterous use of the hand. Physical therapists working to rehabilitate hands with neurological damage understand that tactile sensation is a key indicator of ultimate hand function. Neurophysiologists have identified that rapid reflexive adjustment of grip is essential for handling objects and depends on tactile feedback via the spinal cord. Autonomous robots can deal only with rigid objects in known orientations specifically because they lack tactile feedback. Engineers developing telerobotic manipulators have demonstrated improved performance when vibrotactile feedback is provided via "haptic displays" to the operator's hand. The limiting factor in all of these applications has been the absence of sensitive yet robust sensors that can be incorporated into anthropomorphic mechatronic fingers and used in the diverse and often hostile environments in which hands need to function. We have developed and demonstrated the basic feasibility of novel biomimetic tactile sensors that provide wide dynamic range sensing of normal and shear forces and microvibrations associated with slip and texture. All of their sensing elements and connections are located in and protected by the rigid core of a finger that is covered with skin, pulp and nail elements that are mechanically and cosmetically similar to biological fingers. In this project, we will complete the refinement of the material and transduction properties and integrate them with the signal processing electronics into self- contained modules. These modules can be incorporated mechanically and electronically into a variety of prosthetic and robotic hands intended to provide function for patients with loss of normal hand function as a result of trauma and disease. PUBLIC HEALTH RELEVANCE: Approximately 100,000 Americans are missing one or both arms or hands as a result of trauma or surgical amputation. The development of electromechanical replacement limbs has been hampered by the lack of robust sensors for touch and grip adjustment. We are developing prosthetic fingers that imitate the appearance, mechanical properties and sensory capabilities of human fingers.